Fiber laser refers to a technique of laser-leveled population inversion of laser material caused by high power-density in the optical fiber under the function of pump light, glass optical fiber doped with rare-earth elements are used as gain medium. A positive feedback circuit may be added at proper time to form laser oscillation output.
In the fiber laser, the power thereof and the laser beam quality are two contradictive parameters, that is, the larger the power is, the worse the laser beam quality is; the smaller the power is, the better the laser beam quality is. Currently, users have to choose between the power and the laser beam quality, they may obtain a high power and poor quality one, or a lower power and high quality one. This greatly limits the using scope of the fiber laser and is not benefit for promotion application and the fiber laser.